So sorry to hear about the struggles. You are not alone. Many couples find themselves in similar situations. I agree with you, it sounds like it is better for him to go back to work. When a parent is the source of contamination it can make them feel personally attacked. It can also be hard for fathers especially to see their child suffer and not know how to help the situation. This can often turn into anger, frustration and blame, but underneath that is often fear and hopelessness.
Would he be willing to listen to any podcast episodes? I can pick out ones I think would be the best for the situation you are in?